3FDK

Crystal structure of hydrolase DR0930 with promiscuous catalytic activity


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.277 
  • R-Value Work: 0.232 
  • R-Value Observed: 0.232 

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Literature

Functional annotation and three-dimensional structure of Dr0930 from Deinococcus radiodurans, a close relative of phosphotriesterase in the amidohydrolase superfamily.

Xiang, D.F.Kolb, P.Fedorov, A.A.Meier, M.M.Fedorov, L.V.Nguyen, T.T.Sterner, R.Almo, S.C.Shoichet, B.K.Raushel, F.M.

(2009) Biochemistry 48: 2237-2247

  • DOI: 10.1021/bi802274f
  • Primary Citation of Related Structures:  
    3FDK

  • PubMed Abstract: 
  • Dr0930, a member of the amidohydrolase superfamily in Deinococcus radiodurans, was cloned, expressed, and purified to homogeneity. The enzyme crystallized in the space group P3121, and the structure was determined to a resolution of 2.1 A. The protein folds as a (beta/alpha)7beta-barrel, and a binuclear metal center is found at the C-terminal end of the beta-barrel ...

    Dr0930, a member of the amidohydrolase superfamily in Deinococcus radiodurans, was cloned, expressed, and purified to homogeneity. The enzyme crystallized in the space group P3121, and the structure was determined to a resolution of 2.1 A. The protein folds as a (beta/alpha)7beta-barrel, and a binuclear metal center is found at the C-terminal end of the beta-barrel. The purified protein contains a mixture of zinc and iron and is intensely purple at high concentrations. The purple color was determined to be due to a charge transfer complex between iron in the beta-metal position and Tyr-97. Mutation of Tyr-97 to phenylalanine or complexation of the metal center with manganese abolished the absorbance in the visible region of the spectrum. Computational docking was used to predict potential substrates for this previously unannotated protein. The enzyme was found to catalyze the hydrolysis of delta- and gamma-lactones with an alkyl substitution at the carbon adjacent to the ring oxygen. The best substrate was delta-nonanoic lactone with a kcat/Km of 1.6 x 10(6) M-1 s-1. Dr0930 was also found to catalyze the very slow hydrolysis of paraoxon with values of kcat and kcat/Km of 0.07 min-1 and 0.8 M-1 s-1, respectively. The amino acid sequence identity to the phosphotriesterase (PTE) from Pseudomonas diminuta is 30%. The eight substrate specificity loops were transplanted from PTE to Dr0930, but no phosphotriesterase activity could be detected in the chimeric PTE-Dr0930 hybrid. Mutation of Phe-26 and Cys-72 in Dr0930 to residues found in the active site of PTE enhanced the kinetic constants for the hydrolysis of paraoxon. The F26G/C72I mutant catalyzed the hydrolysis of paraoxon with a kcat of 1.14 min-1, an increase of 16-fold over the wild-type enzyme. These results support previous proposals that phosphotriesterase activity evolved from an ancestral parent enzyme possessing lactonase activity.


    Organizational Affiliation

    Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77842-3012, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
HYDROLASE DR0930A323Deinococcus radioduransMutation(s): 0 
Gene Names: DR_0930
UniProt
Find proteins for Q9RVU2 (Deinococcus radiodurans (strain ATCC 13939 / DSM 20539 / JCM 16871 / LMG 4051 / NBRC 15346 / NCIMB 9279 / R1 / VKM B-1422))
Explore Q9RVU2 
Go to UniProtKB:  Q9RVU2
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download Ideal Coordinates CCD File 
B [auth A], C [auth A]ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
KCX
Query on KCX
AL-PEPTIDE LINKINGC7 H14 N2 O4LYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.277 
  • R-Value Work: 0.232 
  • R-Value Observed: 0.232 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 61.505α = 90
b = 61.505β = 90
c = 205.943γ = 120
Software Package:
Software NamePurpose
ADSCdata collection
PHASERphasing
CNSrefinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-06-30
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance